1. Field of the Invention
The present invention relates to a data record medium, a data recording method, a data recording apparatus, an accessing method, and an accessing apparatus applied to for example optical discs.
2. Description of the Related Art
The standard for compact discs (CD), which are common nowadays, is called compact disc audio (CDDA) and based on standard book (referred to as Red Book). Based on the standard book, various formats have been standardized as so-called CD family. As an extended format of CD, the applicant of the present invention has proposed a data record medium having two record areas. The proposed data record medium has an inner record area (referred to as first area) and an outer record area (referred to as second area). The first area has compatibility with CD. However, the second area does not have it. In the second area, audio data that has been compressed and encrypted is recorded. In addition, the record density of the first area is the same as that of conventional CD (namely, single density). On the other hand, the record density of the second area is twice as high as that of conventional CD (namely, double density).
As a method for recording data in double density, the track pitch is narrowed and/or the linear velocity is decreased. In the case of a read-only disc such as CD, a master disc is created by a mastering device. In this case, since the track pitch and/or linear velocity differ in the two record areas, it takes a time to switch those parameters. Thus, it is difficult to successively record data to the two record areas. As a result, a non-record portion (gap) takes place between the two record areas.
When there is a non-record portion, a problem of how to record addresses takes place. As one method for solving such a problem, addresses may be successively assigned to the first record area and the second record area. In such a case, when the two record areas are successively accessed through the non-record portion, a problem occurs. In other words, the traveling amount of the pickup that accesses the first record area or the second record area differs from that of the pickup that successively accesses the first record area and second record area in the address change amount (difference).
As another method, addresses are zero-reset and assigned to the first record area and the second record area. In this case, the same address is redundantly assigned to the two record areas. Thus, when the first record area and the second record area are successively accessed, a problem takes place. In addition, when the first record area and the second record area are accessed, the traveling amount in the radius direction of the disc is detected by counting the number of tracks that the pickup traverses using a track traverse signal. However, in a non-record portion, since there is no track, when the pickup traverses the non-record portion, the traveling amount in the radius direction cannot be accurately detected.
Therefore, an object of the present invention is to provide a data record medium, a data recording method, a data recording apparatus, an accessing method, and an accessing apparatus that allow a problem of which two areas are not successively accessed due to a non-record portion to be solved.
To solve the above-described problem, a first aspect of the present invention is a data record medium having at least two record area and a non-record area formed therebetween, wherein assuming that addresses are assigned to the non-record area, addresses are assigned to the record areas.
A second aspect of the present invention is a data recording method for recording data to a record medium having at least two record area and a non-record area formed therebetween, wherein assuming that addresses are assigned to the non-record area, addresses are assigned to the record areas.
A third aspect of the present invention is a data recording apparatus for recording data to a record medium having at least two record area and a non-record area formed therebetween, comprising a means for recording data to the record areas so that assuming that addresses are assigned to the non-record area, addresses are assigned to the record areas.
A fourth aspect of the present invention is an accessing method for accessing a data record medium having at least two record areas and a non-record area formed therebetween, addresses being successively assigned to the record areas, comprising the steps of converting the length of the non-record area into the variation amount of an address, and accessing a desired position corresponding to the converted address.
A fifth aspect of the present invention is an accessing apparatus for accessing a data record medium having at least two record areas and a non-record area formed therebetween, addressed being successively assigned to the record areas, comprising a means for converting the length of the non-record area into the variation amount of an address and generating addresses, and a means for accessing a desired position of the data record medium corresponding to the generated addresses.
According to the present invention, even if there is a non-record portion between two record areas, since it is assumed that addresses have been assigned to the non-record portion, the two areas can be successively accessed without problem.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawings.